Exercise device



FIG. 1 is a perspective view of an exercise device, showing my new design;

FIG. 2 is a left side elevation view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a front elevation view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for an exercise device, as shown and described. 